Adult supratentorial low-grade glioma: long-term experience at a single institution

Integrated bioinformatics analysis and experimental validation identified CDCA families as prognostic biomarkers and sensitive indicators for rapamycin treatment of glioma

The cell division cycle associated (CDCA) genes regulate the cell cycle; however, their relationship with prognosis in glioma has been poorly reported in the literature. The Cancer Genome Atlas (TCGA) was utilized to probe the CDCA family in relation to the adverse clinical features of glioma. Glioma single-cell atlas reveals specific expression of CDCA3, 4, 5, 8 in malignant cells and CDCA7 in neural progenitor cells (NPC)-like malignant cells. Glioma data from TCGA, the China Glioma Genome Atlas Project (CGGA) and the gene expression omnibus (GEO) database all demonstrated that CDCA2, 3, 4, 5, 7 and 8 are prognostic markers for glioma. Further analysis identified CDCA2, 5 and 8 as independent prognostic factors for glioma. Lasso regression-based risk models for CDCA families demonstrated that high-risk patients were characterized by high tumor mutational burden (TMB), low levels of microsatellite instability (MSI), and low tumor immune dysfunction and rejection (TIDE) scores. These pointed to immunotherapy for glioma as a potentially viable treatment option Further CDCA clustering suggested that the high CDCA subtype exhibited a high macrophage phenotype and was associated with a higher antigen presentation capacity and high levels of immune escape. In addition, hsa-mir-15b-5p was predicted to be common regulator of CDCA3 and CDCA4, which was validated in U87 and U251 cells. Importantly, we found that CDCAs may indicate response to drug treatment, especially rapamycin, in glioma. In summary, our results suggest that CDCAs have potential applications in clinical diagnosis and as drug sensitivity markers in glioma.

Factors associated with preoperative and postoperative seizures in patients undergoing resection of brain metastases

OBJECTIVE

Epileptic seizures are a common and potentially devastating complication of metastatic brain tumors. Although tumor-related seizures have been described in previous case series, most studies have focused on primary brain tumors and have not differentiated between different types of cerebral metastases. The authors analyzed a large surgical cohort of patients with brain metastases to examine risk factors associated with preoperative and postoperative seizures and to better understand the seizure risk factors of metastatic brain tumors.

METHODS

Patients who underwent resection of a brain metastasis at the University of California, San Francisco (UCSF), were retrospectively reviewed. Patients included in the study were ≥ 18 years of age, required resection of a brain metastasis, and were treated at UCSF. Primary cancers included melanoma, non-small cell lung adenocarcinoma, breast adenocarcinoma, colorectal adenocarcinoma, esophageal adenocarcinoma, gastric adenocarcinoma, renal cell carcinoma, urothelial carcinoma, ovarian carcinoma, cervical squamous cell carcinoma, and endometrial adenocarcinoma. Patients were evaluated for primary cancer type and seizure occurrence, as well as need for use of antiepileptic drugs preoperatively, at time of discharge, and at 6 months postoperatively. Additionally, Engel classification scores were assigned to those patients who initially presented with seizures preoperatively. Univariate and multivariate regression analyses were used to assess the association of tumor type with preoperative seizures.

RESULTS

Data were retrospectively analyzed for 348 consecutive patients who underwent surgical treatment of brain metastases between 1998 and 2019. The cohort had a mean age of 60 years at the time of surgery and was 59% female. The mean and median follow-up durations after the date of surgery for the cohort were 22 months and 10.8 months, respectively. In univariate analysis, frontal lobe location (p = 0.05), melanoma (p = 0.02), KRAS mutation in lung carcinoma (p = 0.04), intratumoral hemorrhage (p = 0.04), and prior radiotherapy (p = 0.04) were associated with seizure presentation. Postoperative checkpoint inhibitor use (p = 0.002), prior radiotherapy (p = 0.05), older age (p = 0.002), distant CNS progression (p = 0.004), and parietal lobe tumor location (p = 0.002) were associated with seizures at 6 months postoperatively. The final multivariate model confirmed the independent effects of tumor location in the frontal lobe and presence of intratumoral hemorrhage as predictors of preoperative seizures, and checkpoint inhibitor use and parietal lobe location were identified as significant predictors of seizures at 6 months postoperatively.

CONCLUSIONS

Within this surgical cohort of patients with brain metastases, seizures were seen in almost a quarter of patients preoperatively. Frontal lobe metastases and hemorrhagic tumors were associated with higher risk of preoperative seizures, whereas checkpoint inhibitor use and parietal lobe tumors appeared to be associated with seizures at 6 months postoperatively. Future research should focus on the effect of metastatic lesion-targeting therapeutic interventions on seizure control in these patients.

Development and validation of a novel survival prediction model for newly diagnosed lower-grade gliomas

OBJECTIVE

Diffuse gliomas are the most common primary gliomas with a poor prognosis. This study aimed to develop and validate prognostic models for predicting the survival probability in newly diagnosed lower-grade glioma (LGG) patients.

METHODS

Detailed data were obtained for newly diagnosed LGG from The Cancer Genome Atlas (TCGA) and the Chinese Glioma Genome Atlas (CGGA) cohorts. Survival was assessed using Cox proportional hazards regression with adjustment for known prognostic factors. The model was established using the TCGA cohort, and independently validated using the CGGA cohort, to predict the 3-, 5-, and 10-year survival probabilities of patients.

RESULTS

Data from 293 patients with newly diagnosed LGG from the TCGA cohort were used to establish a prognostic model, and from 232 patients with primary LGG in the CGGA cohort to validate the model. Age, tumor grade, molecular subtype, tumor resection, and preoperative neurological deficits were included in the prediction model. The Cox regression model had a satisfactory corrected concordance index of 0.8508, 0.8510, and 0.8516 in the internal bootstrap validation at 3, 5, and 10 years, respectively. The calibration plots demonstrated high consistency of the predicted and observed outcomes. The CGGA cohort was used for external validation and showed satisfactory discrimination of 0.7776, 0.7682, and 0.7051 at 3, 5, and 10 years, respectively. The calibration plots demonstrated an acceptable calibration capability in the external validation.

CONCLUSIONS

This study established and validated a prognostic model to predict the survival probability of patients with newly diagnosed LGG. The model performed well in discrimination and calibration with ease of use, speed, accessibility, interpretability, and generalizability. An easily used nomogram based on the Cox model was established for clinical application. Moreover, a free, easy-to-use software interface based on the nomogram is provided online.

Malignant Progression of Diffuse Low-grade Gliomas: A Systematic Review and Meta-analysis on Incidence and Related Factors

Malignant progression of diffuse low-grade glioma (LGG) is a critical event affecting patient survival; however, the incidence and related factors have been inconsistent in literature. According to the PRISMA guidelines, we systematically reviewed articles from 2009, meta-analyzed the incidence of malignant progression, and clarified factors related to the transformation. Forty-one articles were included in this study (n = 7,122; n, number of patients). We identified two definitions of malignant progression: histologically proven (Htrans) and clinically defined (Ctrans). The malignant progression rate curves of Htrans and Ctrans were almost in parallel when constructed from the results of meta-regression by the mean follow-up time. The true transformation rate was supposed to lie between the two curves, approximately 40% at the 10-year mean follow-up. Risk of malignant progression was evaluated using hazard ratio (HR). Pooled HRs were significantly higher in tumors with a larger pre- and postoperative tumor volume, lower degree of resection, and notable preoperative contrast enhancement on magnetic resonance imaging than in others. Oligodendroglial histology and IDH mutation (IDHm) with 1p/19q codeletion (Codel) also significantly reduced the HRs. Using Kaplan-Meier curves from eight studies with molecular data, we extracted data and calculated the 10-year malignant progression-free survival (10yMPFS). The 10yMPFS in patients with IDHm without Codel was 30.4% (95% confidence interval [95% CI]: 22.2-39.0) in Htrans and 38.3% (95% CI: 32.3-44.3) in Ctrans, and that with IDHm with Codel was 71.7% (95% CI: 61.7-79.5) in Htrans and 62.5% (95% CI: 55.9-68.5) in Ctrans. The effect of adjuvant radiotherapy or chemotherapy could not be determined.

Risk Stratification in Low Grade Glioma: A Single Institutional Experience

Background

Low grade gliomas (LGG) are most often noted with the unpredictable overall survival and progression to higher grades. Objective: In the present study, we analyze the clinicopathological features influencing the prognostic outcomes and compared the features with criteria developed by EORTC.

Materials and Methods

We observed the 130 LGG clinical cases in single institute and maintained the follow-up for more than 5 years. In addition, the molecular details were confirmed with markers as IDH, 1p/19q codeletion, p53 and ATRX mutations.

Results

The mean age of patients as 37.67 years and male population contributing to 70%. We observed biased incidence among the male population with dominating occurrence at frontal and parietal lobes in the brain. 40.8% patients had oligodendroglioma, 33.8% astrocytoma, 19.2% oligoastrocytoma and 2.3% gemistocytic astrocytoma pathology. Patients who were subjected to chemotherapy and radiotherapy were noted with average survival of 29 months. Oligodendroglial tumors were found with progression free survival (PFS) of 25 months, oligoastrocytoma cases with 32 months, diffuse astrocytoma cases with 23 months while the gemistocytic astrocytoma cases had 22 months. The PFS for LGG cases was 4.7 years while the overall survival was 4.9 years. Mean survival of patients with KPS score <70 and >70 was 1.5 & 4.9 years respectively. 64 patients were observed with the tumor size >5 cm. In total, 72.3% of the patients were underwent GTR, 23.3% STR and 3.8% underwent biopsy.

Conclusion

Taken together, the clinical symptoms, expression of molecular markers and the prognosis details provided by our results can help for better management of LGG cases. We further propose to use following five factors to accurately describe the prognosis and tumor recurrence: 1) Age >50 years, 2) tumor size >5 cm, 3) MIB index >5%, 4) KPS score < 70 and 5) gemistocytic pathology.

5-ALA Fluorescence Is a Powerful Prognostic Marker during Surgery of Low-Grade Gliomas (WHO Grade II)-Experience at Two Specialized Centers

The prediction of the individual prognosis of low-grade glioma (LGG) patients is limited in routine clinical practice. Nowadays, 5-aminolevulinic acid (5-ALA) fluorescence is primarily applied for improved intraoperative visualization of high-grade gliomas. However, visible fluorescence is also observed in rare cases despite LGG histopathology and might be an indicator for aggressive tumor behavior. The aim of this study was thus to investigate the value of intraoperative 5-ALA fluorescence for prognosis in LGG patients. We performed a retrospective analysis of patients with newly diagnosed histopathologically confirmed LGG and preoperative 5-ALA administration at two independent specialized centers. In this cohort, we correlated the visible intraoperative fluorescence status with progression-free survival (PFS), malignant transformation-free survival (MTFS) and overall survival (OS). Altogether, visible fluorescence was detected in 7 (12%) of 59 included patients in focal intratumoral areas. At a mean follow-up time of 5.3 ± 2.9 years, patients with fluorescing LGG had significantly shorter PFS (2.3 ± 0.7 vs. 5.0 ± 0.4 years; p = 0.01), MTFS (3.9 ± 0.7 vs. 8.0 ± 0.6 years; p = 0.03), and OS (5.4 ± 1.0 vs. 10.3 ± 0.5 years; p = 0.01) than non-fluorescing tumors. Our data indicate that visible 5-ALA fluorescence during surgery of pure LGG might be an already intraoperatively available marker of unfavorable patient outcome and thus close imaging follow-up might be considered.

Outcomes of infratentorial cranial surgery for tumor resection in older patients: An analysis of the National Surgical Quality Improvement Program

Background:

Poorer outcomes for infratentorial tumor resection have been reported. There is a lack of large multicenter analyses describing infratentorial surgery outcomes in older patients. We characterized outcomes in patients aged ≥65 years undergoing infratentorial cranial surgery.

Methods:

The National Surgical Quality Improvement Project database was queried from 2012 to 2018 for patients ≥18 years undergoing elective infratentorial cranial surgery for tumor resection. Patients were grouped into 65–74 years, ≥75 years, and 18–64 years cohorts. Multivariable regressions compared outcome measures.

Results:

Of 2212 patients, 28.3% were ≥65 years, of whom 24.8% were ≥75 years. Both older subpopulations had worse American Society of Anesthesiologists classification compared to controls (P < 0.01) and more comorbidities. Patients 65–74 and ≥75 years had higher rates of major complication (adjusted odds ratio [aOR] = 1.77, 95% CI = 1.13–2.79 and aOR = 3.44, 95% CI = 1.96–6.02, respectively), prolonged length of stay (LOS) (aOR = 1.89, 95% CI = 1.15–3.12 and aOR = 3.00, 95% CI = 1.65–5.44, respectively), and were more likely to be discharged to a location other than home (aOR = 2.43, 95% CI =1.73–3.4 and aOR = 3.41, 95% CI = 2.18–5.33, respectively) relative to controls. Patients ≥75 had higher rates of readmission (aOR = 1.86, 95% CI = 1.13–3.08) and mortality (aOR = 3.28, 95% CI = 1.21–8.89) at 30 days.

Conclusion:

Patients ≥65 years experienced more complications, prolonged LOS, and were less often discharged home than adults <65 years. Patients ≥75 years had higher rates of 30-day readmission and mortality. There is a need for careful preoperative optimization in older patients undergoing infratentorial tumor cranial surgery.

A Case of Diffuse Astrocytoma with 32-year Survival after Boron Neutron Capture Therapy

A 39-year-old man had received boron neutron capture therapy (BNCT) for a grade II astrocytoma (compatible with diffuse astrocytoma, not otherwise specified in the WHO 2016 criteria). He returned to his previous work after surgery, but, 7 years later, he suddenly developed seizures, and his health condition deteriorated. Therefore, he underwent a second surgery. The mass removed in the second operation was mostly necrotic as a result of previous radiation treatment. He then showed no signs of recurrence and did not require any treatment other than antiepileptic drugs for 25 years. He was able to be employed by a listed company until the age of 65 years for light jobs as a physically handicapped individual. This case suggests the effectiveness of BNCT even for rather low-grade astrocytomas.

Educational Case: Histologic and Molecular Features of Diffuse Gliomas

The following fictional cases are intended as a learning tool within the Pathology Competencies for Medical Education (PCME), a set of national standards for teaching pathology. These are divided into three basic competencies: Disease Mechanisms and Processes, Organ System Pathology, and Diagnostic Medicine and Therapeutic Pathology. For additional information, and a full list of learning objectives for all three competencies, seehttp://journals.sagepub.com/doi/10.1177/2374289517715040.¹

Prediagnostic symptoms and signs of adult glioma: the patients' view

BACKGROUND

Little is known about the symptoms glioma patients experience in the year before diagnosis, either or not resulting in health care usage. This study aimed to determine the incidence of symptoms glioma patients experienced in the year prior to diagnosis, and subsequent visits to a general practitioner (GP).

METHODS

Glioma patients were asked to complete a 30-item study-specific questionnaire focusing on symptoms they experienced in the 12 months before diagnosis. For each indicated symptom, patients were asked whether they consulted the GP for this issue.

RESULTS

Fifty-nine patients completed the questionnaires, 54 (93%) with input of a proxy. The median time since diagnosis was 4 months (range 1-12). The median number of symptoms experienced in the year before diagnosis was similar between gliomas with favourable and poor prognosis, i.e. 6 (range 0-24), as were the five most frequently mentioned problems: fatigue (n = 34, 58%), mental tiredness (n = 30, 51%), sleeping disorder (n = 24, 41%), headache (n = 23, 39%) and stress (n = 20, 34%). Twenty-six (44%) patients visited the GP with at least one issue. Patients who did consult their GP reported significantly more often muscle weakness (11 vs 3, p = 0.003) than patients who did not, which remained significant after correction for multiple testing, which was not the case for paralysis in hand/leg (10 vs 4), focussing (11 vs 6) or a change in awareness (9 vs 4).

CONCLUSIONS

Glioma patients experience a range of non-specific problems in the year prior to diagnosis, but only patients who consult the GP report more often neurological problems.

Prediagnostic presentations of glioma in primary care: a case-control study

Aim:

This study aimed to assess the prevalence of symptoms glioma patients may present with to the general practitioner, and whether these can be distinguished from patients with other CNS disorders or any other condition.

Methods:

Glioma patients were matched to CNS patients and ‘other controls’ using anonymized general practitioner registries. Prevalences were evaluated in the 5 years prior to diagnosis.

Result:

CNS patients reported significantly more motor symptoms in the period 60–24 months, (p = 0.039). Moreover, <6 months before diagnosis CNS patients differed significantly in mood disorders/fear compared with ‘other controls’ (p = 0.012) but not glioma patients (p = 0.816).

Conclusion:

Glioma patients could not be distinguished from both control groups with respect to the number or type of prediagnostic symptoms.

The Germline Variants rs61757955 and rs34988193 Are Predictive of Survival in Lower Grade Glioma Patients

Lower grade gliomas are invasive brain tumors that are difficult to completely resect neurosurgically. They often recur following resection and progress, resulting in death. Although previous studies have shown that specific germline variants increase the risk of tumor formation, no previous study has screened many germline variants to identify variants predictive of survival in patients with glioma. In this study, we present an approach to identify the small fraction of prognostic germline variants from the pool of over four million variants that we variant called in The Cancer Genome Atlas whole-exome sequencing and RNA sequencing datasets. We identified two germline variants that are predictive of poor patient outcomes by Cox regression, controlling for eleven covariates. rs61757955 is a germline variant found in the 3' UTR of GRB2 associated with increased KRAS signaling, CIC mutations, and 1p/19q codeletion. rs34988193 is a germline variant found in the tumor suppressor gene ANKDD1a that causes an amino acid change from lysine to glutamate. This variant was found to be predictive of poor prognosis in two independent lower grade glioma datasets and is predicted to be within the top 0.06% of deleterious mutations across the human genome. The wild-type residue is conserved in all 22 other species with a homologous protein. IMPLICATIONS: This is the first study presenting an approach to screening many germline variants to identify variants predictive of survival and our application of this methodology revealed the germline variants rs61757955 and rs34988193 as being predictive of survival in patients with lower grade glioma.

Diffuse Low-Grade Glioma - Changing Concepts in Diagnosis and Management: A Review

Though diffuse low-grade gliomas (dLGGs) represent only 15% of gliomas, they have been receiving increasing attention in the past decade. Significant advances in knowledge of the natural history and clinical diversity have been documented, and an improved pathological classification of gliomas that integrates histological features with molecular markers has been issued by the WHO. Advances in the radiological assessment of dLGG, particularly new magnetic resonance imaging scanning sequences, allow improved diagnostic and prognostic information. The management paradigms are evolving from “wait and watch” of the past to more active interventional therapy to obviate the risk of malignant transformation. New surgical technologies allow more aggressive surgical resections with a reduction of morbidity. Many reports suggest the association of gross total resection with longer overall survival and progression-free survival in addition to better seizure control. The literature also shows the use of chemotherapeutics and radiation therapy as important adjuncts to surgery. The goals of management have has been increasing survival with increasing stress on quality of life. Our review highlights the recent advances in the molecular diagnosis and management of dLGG with trends toward multidisciplinary and multimodality management of dLGG with an aim to surgically resect the primary disease, followed by chemoradiation in cases of progressive or recurrent disease.

Patterns of re-irradiation for recurrent gliomas and validation of a prognostic score

PURPOSE OR OBJECTIVE

Re-irradiation is a generally accepted method for salvage treatment in patients with recurrent glioma. However, no standard radiation regimen has been defined. This study aims to compare the efficacy and safety of different treatment regimens and to independently externally validate a recently published reirradiation risk score.

MATERIAL AND METHODS

We retrospectively analyzed a cohort of patients with recurrent malignant glioma treated with salvage conventionally fractionated (CFRT), hypofractionated (HFRT) or stereotactic radiotherapy (SRT) between 2007 and 2017 at the University Medical Centers in Utrecht and Groningen.

RESULTS

Of the 121 patients included, 60 patients (50%) underwent CFRT, 22 (18%) HFRT and 39 (32%) SRT. The primary tumor was grade II-III in 52 patients and grade IV in 69 patients with median Overall Survival (mOS) since first surgery of 113 [Interquartile range: 53.2-137] and 39.7 [24.6-64.9] months respectively (p < 0.01). Overall, mOS from the first day of re-irradiation was 9.7 months [6.5-14.6]. No significant difference in mOS was found between the treatment groups. In multivariate analysis, the Karnofsky performance scale ≥70% (p < 0.01), re-irradiation for first recurrence (p = 0.02), longer time interval between RT start dates (p < 0.01) and smaller planning target volume (p < 0.05) were significant favorable prognostic factors. The reirradiation risk score was validated.

CONCLUSION

In our series, mOS after reirradiation was sufficient to justify use of this modality. Until a reliable treatment decision tool is developed based on larger retrospective research, the decision for re-irradiation schedule should remain personalized and based on a multidisciplinary evaluation of each patient.

Seizures at presentation are correlated with better survival outcomes in adult diffuse glioma: A systematic review and meta-analysis

PURPOSE

Seizures are the most common presenting sign of patients with diffuse glioma. In the current study, we performed a meta-analysis to determine the correlation of seizures at presentation to survival outcomes in adult diffuse glioma, and the possible mechanisms were also discussed.

METHODS

A comprehensive literature search was performed in PUBMED, EMBASE, Web of Science and the Cochrane Central Register of Controlled Trials. The pooled hazard ratio (HR) and corresponding 95% confidence interval (CI) were used to estimate effects. Heterogeneity among studies and publication bias were also evaluated.

RESULTS

11 studies with 2088 patients were finally included for the current meta-analysis. Seizure-free preoperatively was significantly associated with a poor overall survival in patients with diffuse glioma, the pooled HR was 1.73 (95% CI 1.43-2.08, Z = 5.71, p < 0.001). Subgroup analysis was also performed by tumor grade, the same association was identified in both low-grade glioma (pooled HR 2.49, 95% CI 1.47-4.20, Z = 3.40, p < 0.001) and glioblastoma (pooled HR 1.46, 95% CI 1.27-1.68, Z = 5.24, p < 0.001). A significant correlation of seizure-free with a poor progression-free survival was also identified (pooled HR 1.42, 95% CI 1.06-1.92, Z = 2.33, p = 0.02), although only 3 studies comprising 368 patients were included.

CONCLUSION

The current study determined that seizures at presentation were an independent predictor of better survival outcomes in adult diffuse glioma. It is the first study which provides a comprehensive standardized assessment of the association between seizures at presentation with long-term survival outcomes in patients with diffuse glioma.

Prognostic markers for survival in patients with oligodendroglial tumors; a single-institution review of 214 cases

Background

In the 2016 WHO classification, the diagnosis of oligodendroglioma has been restricted to IDH mutated, 1p19q codeleted tumors (IDHmut-codel). IDHmut oligoastrocytoma is now classified either as oligodendroglioma or astrocytoma based on presence of 1p19q codeletion. There is growing evidence that this molecular classification more closely reflects patient outcome. Due to the strong association between IDHmut-codel with oligodendroglial morphology, the additional impact of these markers on prognostic accuracy is largely unknown. Our aim was to assess the prognostic impact of IDHmut-codel in an unselected cohort of morphologically classified oligodendroglial tumors.

Methods

We performed a retrospective chart review of oligodendroglial tumors (WHO grade II and III) operated since 1983. A total of 214 tumors were included, and molecular information was available for 96 tumors. The prognostic impact of IDHmut-codel together with clinical parameters was analyzed by multivariate Cox regression.

Results

IDHmut-codel was registered in 64 tumors while for 150 tumors the molecular profile was negative for IDHmut-codel, unknown or incomplete. Comparison between the two groups showed that patients with IDHmut-codel tumors were younger (42 vs. 48 years), had more frequent frontal tumor location (48 vs. 33%) and presented more often with seizures (72 vs. 51%) and no signs of neurological impairment (14 vs. 30%) than patients harboring tumors with unknown or incomplete molecular profile. Multivariate survival analysis identified young age (HR 1.78 ≥ 40 years), the absence of neurological deficits or personality changes (HR 0.57), frontal tumor location (HR 0.64) and the presence of IDHmut-codel (HR 0.50) as independent predictors for longer survival, whereas tumor grade was not.

Conclusion

In this unselected single-institution cohort, the presence of IDHmut-codel was associated with more beneficial clinical parameters and was identified as an independent prognostic factor. We conclude that the classical oligodendroglioma genotype provides additional prognostic data beyond clinical characteristics, morphology and tumor grade.

Effect of anesthesia depth on postoperative clinical outcome in patients with supratentorial tumor (DEPTH): study protocol for a randomized controlled trial

INTRODUCTION

Recent studies have shown that deep anaesthesia is associated with poor outcomes. However, no randomised controlled trials have been conducted to test the causality in patients undergoing brain tumour resection.

METHODS AND ANALYSIS

DEPTH is a multicenter, randomised, parallel-group, blind trial. The depth of general anaesthesia will be monitored using the bispectral index (BIS). Patients elected for supratentorial tumour resection will be randomly allocated to the deep or the light anaesthesia group in which the target BIS value is 35 or 50, respectively. BIS will be maintained at the target value for more than 90% of the total anaesthesia period. The primary outcome is the disability-free survival rate at postoperative 30 days and 1 year. The secondary outcomes are the mortality and morbidity within 30 days after surgery.

ETHICS APPROVAL AND DISSEMINATION

Ethical approval has been granted by the Medical Ethics Committee of Beijing Tiantan Hospital, Capital Medicine University. The reference number is KY2016-059-02. The results of this study will be disseminated through presentations at scientific conferences and publication in scientific journals.

TRIAL REGISTRATION

NCT03033693.

Identifying clinical risk in low grade gliomas and appropriate treatment strategies, with special emphasis on the role of surgery

INTRODUCTION

Diffuse low-grade glioma (DLGG) is a chronic tumoral disease that ineluctably grows, migrates along white matter pathways, and progresses to a higher grade of malignancy. Areas covered: To determine the best individualized treatment attitude for each DLGG patient, and to redefine it over the years, i.e. to optimize the 'onco-functional balance' of serial and multimodal therapies, the understanding of the natural history of this chronic disease is crucial but not sufficient. A paradigmatic shift is to tailor the individual management according to the dynamic relationships between DLGG course and neural remodeling. In this spirit, a better knowledge of brain plasticity in a connectomal account of cerebral processing has enabled a dramatic improvement of both oncological and functional outcomes in DLGG patients, by increasing overall survival while preserving (or even improving) the quality of life. Expert commentary: Here, we propose an individualized and recursive therapeutic strategy in DLGG, leading to the concept of a 'personalized functional neuro-oncology', by emphasizing the role of early and maximal safe surgical resection(s) reliably achieved using intraoperative mapping of cortico-subcortical networks in awake patients.

Genotyping low-grade gliomas among Hispanics

Background

Low-grade gliomas (LGGs) are classified by the World Health Organization as astrocytoma (DA), oligodendroglioma (OD), and mixed oligoastrocytoma (OA). TP53 mutation and 1p19q codeletion are the most-commonly documented molecular abnormalities. Isocitrate dehydrogenase (IDH) 1/2 mutations are frequent in LGGs; however, IDH-negative gliomas can also occur. Recent research suggests that ATRX plays a significant role in gliomagenesis.

Methods

We investigated p53 and Olig2 protein expression, and MGMT promoter methylation, 1p19q codeletion, IDH, and ATRX status in 63 Colombian patients with LGG. The overall survival (OS) rate was estimated and compared according to genotype.

Results

The most common histology was DA, followed by OD and OA. IDH1/2 mutations were found in 57.1% and MGMT+ (positive status of MGMT promoter methylation methyl-guanyl-methyl-transferase gene) in 65.1% of patients, while overexpression of p53 and Olig2 was present in 30.2% and 44.4%, respectively, and 1p19q codeletion in 34.9% of the patients. Overexpression of ATRX was analyzed in 25 patients, 16% tested positive and were also mutations in isocitrate dehydrogenase and negative 1p19q-codelition. The median follow-up was 15.8 months (95% CI, 7.6-42.0) and OS was 39.2 months (95% CI, 1.3-114). OS was positively and significantly affected by MGMT+, 1p19q codeletion, surgical intervention extent, and number of lobes involved. Multivariate analysis confirmed that MGMT methylation status and 1p19q codeletion affected OS.

Conclusions

This is the first study evaluating the molecular profile of Hispanic LGG patients. Findings confirmed the prognostic relevance of MGMT methylation and 1p19q codeletion, but do not support IDH1/2 mutation as a relevant marker. The latter may be explained by sample size and selection bias. ATRX alterations were limited to patients with DA and were mutations in isocitrate dehydrogenase and negative 1p19q-codelition.

Astrocytic gliomas WHO grades II and III

World Health Organization grades II and III lower-grade astrocytomas are a challenging area in neuro-oncology. One the one hand, for proper diagnosis, the analysis of molecular factors, especially mutation status of isocitrate dehydrogenase and 1p/19q status in the tumor status needs to be done in addition to classical neuropathology. Further, the high clinical and prognostic value of a maximal safe resection requires a profound knowledge of presurgical diagnosis and surgical as well as imaging techniques to ensure optimal outcome for patients. Also medical treatment may be more intensive than previously believed, with randomized trials providing evidence for a benefit in overall survival by combined chemoradiation versus radiation alone. A critical problem concerns the considerable undesirable effects of therapeutic interventions on long-term health-related quality of life, cognitive and functional outcome as well as future developments in this still difficult disease that will need to be addressed in future trials.

The role of radiotherapy in the management of patients with diffuse low grade glioma: A systematic review and evidence-based clinical practice guideline

QUESTIONS

(1) What is the optimal role of external beam radiotherapy in the management of adult patients with newly diagnosed low-grade glioma (LGG) in terms of improving outcome (i.e., survival, complications, seizure control or other reported outcomes of interest)? (2) Which radiation strategies (dose, timing, fractionation, stereotactic radiation, brachytherapy, chemotherapy) improve outcomes compared to standard external beam radiation therapy in the initial management of low grade gliomas in adults? (3) Do specific factors (e.g., age, volume, extent of resection, genetic subtype) identify subgroups with better outcomes following radiation therapy than the general population of adults with newly diagnosed low-grade gliomas?

TARGET POPULATION

These recommendations apply to adults with newly diagnosed diffuse LGG.

RECOMMENDATIONS

OUTCOMES IN ADULT PATIENTS WITH NEWLY DIAGNOSED LOW GRADE GLIOMA TREATED WITH RADIOTHERAPY: Level I Radiotherapy is recommended in the management of newly diagnosed low-grade glioma in adults to prolong progression free survival, irrespective of extent of resection. Level II Radiotherapy is recommended in the management of newly diagnosed low grade glioma in adults as an equivalent alternative to observation in preserving cognitive function, irrespective of extent of resection. Level III Radiotherapy is recommended in the management of newly diagnosed low grade glioma in adults to improve seizure control in patients with epilepsy and subtotal resection. Level III Radiotherapy is recommended in the management of newly diagnosed low-grade glioma in adults to prolong overall survival in patients with subtotal resection. Level III Consideration of the risk of radiation induced morbidity, including cognitive decline, imaging abnormalities, metabolic dysfunction and malignant transformation, is recommended when the delivery of radiotherapy is selected in the management of newly diagnosed low-grade glioma in adults. STRATEGIES OF RADIOTHERAPY IN ADULT PATIENTS WITH NEWLY DIAGNOSED LOW GRADE GLIOMA: Level I Lower dose radiotherapy is recommended as an equivalent alternative to higher dose immediate postoperative radiotherapy (45-50.4 vs. 59.4-64.8 Gy) in the management of newly diagnosed low-grade glioma in adults with reduced toxicity. Level III Delaying radiotherapy until recurrence or progression is recommended as an equivalent alternative to immediate postoperative radiotherapy in the management of newly diagnosed low-grade glioma in adults but may result in shorter time to progression. Level III The addition of chemotherapy to radiotherapy is not recommended over whole brain radiotherapy alone in the management of low-grade glioma, as it provides no additional survival benefit. Level III Limited-field radiotherapy is recommended over whole brain radiotherapy in the management of low-grade glioma. Level III Either stereotactic radiosurgery or brachytherapy are recommended as acceptable alternatives to external radiotherapy in selected patients. PROGNOSTIC FACTORS IN ADULT PATIENTS WITH NEWLY DIAGNOSED LOW GRADE GLIOMA TREATED WITH RADIOTHERAPY: Level II It is recommended that age greater than 40 years, astrocytic pathology, diameter greater than 6 cm, tumor crossing the midline and preoperative neurological deficit be considered as negative prognostic indicators when predicting overall survival in adult low grade glioma patients treated with radiotherapy. Level II It is recommended that smaller tumor size, extent of surgical resection and higher mini-mental status exam be considered as positive prognostic indicators when predicting overall survival and progression free survival in patients in adult low grade glioma patients treated with radiotherapy. Level III It is recommended that seizures at presentation, presence of oligodendroglial histological component and 1p19q deletion (along with additional relevant factors-see Table 1) be considered as positive prognostic indicators when predicting response to radiotherapy in adults with low grade gliomas. Level III It is recommended that increasing age, decreasing performance status, decreasing cognition, presence of astrocytic histological component (along with additional relevant factors (see Tables 1, 2) be considered as negative prognostic indicators when predicting response to radiotherapy.

The role of surgery in the management of patients with diffuse low grade glioma: A systematic review and evidence-based clinical practice guideline

QUESTION

Should patients with imaging suggestive of low grade glioma (LGG) undergo observation versus treatment involving a surgical procedure?

TARGET POPULATION

These recommendations apply to adults with imaging suggestive of a WHO grade 2 glioma (oligodendroglioma, astrocytoma, or oligo-astrocytoma).

RECOMMENDATIONS

Surgical resection is recommended over observation to improve overall survival for patients with diffuse low-grade glioma (Level III) although observation has no negative impact on cognitive performance and quality of life (Level II).

QUESTION

What is the impact of extent of resection on progression free survival (PFS) or overall survival (OS) in LGG patients?

TARGET POPULATION

These recommendations apply to adults with imaging suggestive of a WHO grade 2 glioma (oligodendroglioma, astrocytoma, or oligo-astrocytoma).

RECOMMENDATIONS

IMPACT OF EXTENT OF RESECTION ON PFS:

LEVEL II

It is recommended that GTR or STR be accomplished instead of biopsy alone when safe and feasible so as to decrease the frequency of tumor progression recognizing that the rate of progression after GTR is fairly high.

IMPACT OF EXTENT OF RESECTION ON OS

LEVEL III

Greater extent of resection can improve OS in LGG patients.

QUESTION

What tools are available to increase extent of resection in LGG patients?

TARGET POPULATION

These recommendations apply to adults with imaging suggestive of a WHO grade 2 glioma (oligodendroglioma, astrocytoma, or oligo-astrocytoma).

RECOMMENDATIONS

INTRAOPERATIVE MRI DURING SURGERY:

LEVEL III

The use of intraoperative MRI should be considered as a method of increasing the extent of resection of LGGs.

QUESTION

What is the impact of surgical resection on seizure control and accuracy of pathology in low grade glioma patients?

TARGET POPULATION

These recommendations apply to adults with imaging suggestive of a WHO grade 2 glioma (oligodendroglioma, astrocytoma, or oligo-astrocytoma).

RECOMMENDATIONS

SURGICAL RESECTION AND SEIZURE CONTROL:

LEVEL III

After taking into account the patient's clinical status and tumor location, gross total resection is recommended for patients with diffuse LGG as a way to achieve more favorable seizure control.

ACCURACY OF DIAGNOSIS

LEVEL III

Taking into account the patient's clinical status and tumor location, surgical resection should be carried out to maximize the chance of accurate diagnosis.

QUESTION

What tools can improve the safety of surgery for LGGs in eloquent locations?

TARGET POPULATION

These recommendations apply to adults with imaging suggestive of a WHO grade 2 glioma (oligodendroglioma, astrocytoma, or oligo-astrocytoma).

RECOMMENDATIONS

PREOPERATIVE IMAGING:

LEVEL III

It is recommended that preoperative functional MRI and diffusion tensor imaging be utilized in the appropriate clinical setting to improve functional outcome after surgery for LGG.

INTRAOPERATIVE MAPPING OF TUMORS IN ELOQUENT AREAS

LEVEL III

Intraoperative mapping is recommended for patients with diffuse LGGs in eloquent locations compared to patients with non-eloquently located diffuse LGGs as a way of preserving function.

Overall survival in adult patients with low-grade, supratentorial glioma: Ten years' follow up at a single institution

Background:

Low-grade gliomas (LGGs) are the second most prevalent type of primary brain tumors in adults. The prognosis for LGGs can differ according to the clinical-pathological prognostic factors determined during diagnosis and treatment. The purpose of this study was to identify 10-year, disease-free survival (DFS), 10-year overall survival (OS), and related clinical-pathological prognostic factors of adult patients with supratentorial, low-grade gliomas who were treated with or without surgery and radiation therapy.

Methods:

The study included 110 patients who were confirmed to have low-grade, supratentorial gliomas and who had received surgery and adjuvant radiation therapy or salvage radiotherapy as part of their treatment. These patients were followed by the radiation-oncology ward at Shohada-e-Tajrish Hospital in Tehran, Iran, between 2002 and 2012. The log-rank test (univariate) and the Cox proportional hazards model (multivariate) were used to examine the 10-year DFS and OS and to assess the strengths of various histo-clinical factors relative to 10-year DFS and OS.

Results:

The study included 110 patients for whom 10-year DFS and OS were found to be 23 and 28%, respectively. Favorable prognostic factors in the univariate analysis using the Kaplan-Meier 10-year OS analysis were the following: age below 40, karnofsky performance status (KPS) more than 70, the presence of oligodendroglioma, tumor size of < 5 cm, and gross-total resection (p=0.02, p=0.01, p=0.03, p=0.01, p=0.02, respectively). Good prognostic factors in multivariate analysis using the Cox regression model were as follows: age below 40, the presence of oligodendroglioma, tumor size< 5 cm, and gross total resection in10-year OS (p=0.01, p=0.03, p=0.00, p=0.02, respectively).

Conclusions:

Gross-total resection, tumor size < 5 cm, age below 40, and the presence of oligodendroglioma had better 10-year DFS and OS rates. We recommend that all patients with LGG tumors be referred to neuro-oncology centers that have sufficient experience to achieve the best results of treatment.

Diffusely infiltrating astrocytomas: pathology, molecular mechanisms and markers

Diffusely infiltrating astrocytomas include diffuse astrocytomas WHO grade II and anaplastic astrocytomas WHO grade III and are classified under astrocytic tumours according to the current WHO Classification. Although the patients generally have longer survival as compared to those with glioblastoma, the timing of inevitable malignant progression ultimately determines the prognosis. Recent advances in molecular genetics have uncovered that histopathologically diagnosed astrocytomas may consist of two genetically different groups of tumours. The majority of diffusely infiltrating astrocytomas regardless of WHO grade have concurrent mutations of IDH1 or IDH2, TP53 and ATRX. Among these astrocytomas, no other genetic markers that may distinguish grade II and grade III tumours have been identified. Those astrocytomas without IDH mutation tend to have a distinct genotype and a poor prognosis comparable to that of glioblastomas. On the other hand, diffuse astrocytomas that arise in children do not harbour IDH/TP53 mutations, but instead display mutations of BRAF or structural alterations involving MYB/MYBL1 or FGFR1. A molecular classification may thus help delineate diffusely infiltrating astrocytomas into distinct pathogenic and prognostic groups, which could aid in determining individualised therapeutic strategies.

Age-associated brain regions in gliomas: a volumetric analysis

Both age of patients and tumor location are associated with tumor origin, genetic characteristics, and prognosis. The objective of this study was to investigate the relationship between tumor location and age at diagnosis in a large cohort of patients with a primary diagnosis of glioma. We consecutively enrolled a cohort of 200 adults with glioblastoma and another cohort of 200 adults with diffuse low-grade gliomas. The magnetic resonance images of all tumors were manually segmented and then registered to a standard brain space. By using voxel-by-voxel regression analysis, specific brains regions associated with advanced age at tumor diagnosis were localized. In the low-grade gliomas cohort, the brain regions associated with advanced age at tumor diagnosis were mainly located in the right middle frontal region, while a region in the left temporal lobe, particularly at the subgranular zone, was associated with lower age at tumor diagnosis. In the glioblastoma cohort, the brain regions associated with advanced age at tumor diagnosis were mainly located in the temporal lobe, particularly at the posterior region of the subventricular zones. A region in the left inferior frontal region was associated with lower age at tumor diagnosis. Significant differences in the age of patients were found between tumors located in the identified regions and those located elsewhere in both cohorts. The current study demonstrated the correlation between tumor location and age at diagnosis, which implies differences in the origin of gliomas in young and older patients.

A radiosensitivity gene signature in predicting glioma prognostic via EMT pathway

A 31-gene signature derived by integrating four different microarray experiments, has been found to have a potential for predicting radiosensitivity of cancer cells, but it was seldom validated in clinical cancer samples. We proposed that the gene signature may serve as a predictive biomarker for estimating the overall survival of radiation-treated patients. The significance of gene signature was tested in two previously published datasets from Gene Expression Omnibus (GEO) and The Cancer Genome Altas (TCGA), respectively. In GEO data set, patients predicted to be radiosensitive(RS) had an improved overall survival when compared with radioresistant(RR) patients in either radiotherapy(RT)-treated or non radiotherapy(RT)-treated subgroups(p<0.0001 in the RT-treated group). Multivariate Cox regression analysis showed that the gene signature is the strongest predictor(p=0.0093) in the RT-treated subgroup of patients. However, it does not remain significant (p=0.7668) in non radiotherapy-treated group when adjusting for age and Karnofsky performance score (KPS) as covariates. Similarly, in the TCGA data set, radiotherapy-treated glioblastoma multiforme(GBM) patients assigned to RS group had an improved overall survival compared with RR group(p<0.0001). Geneset enrichment analysis(GSEA) analysis revealed that enrichment of epithelial mesenchymal transition(EMT) pathway was observed with radioresistant phenotype. These results suggest that the signature is a predictive biomarker for radiation-treated glioma patients' prognostic.

Mutational landscape and clonal architecture in grade II and III gliomas

Grade II and III gliomas are generally slowly progressing brain cancers, many of which eventually transform into more aggressive tumors. Despite recent findings of frequent mutations in IDH1 and other genes, knowledge about their pathogenesis is still incomplete. Here, combining two large sets of high-throughput sequencing data, we delineate the entire picture of genetic alterations and affected pathways in these glioma types, with sensitive detection of driver genes. Grade II and III gliomas comprise three distinct subtypes characterized by discrete sets of mutations and distinct clinical behaviors. Mutations showed significant positive and negative correlations and a chronological hierarchy, as inferred from different allelic burdens among coexisting mutations, suggesting that there is functional interplay between the mutations that drive clonal selection. Extensive serial and multi-regional sampling analyses further supported this finding and also identified a high degree of temporal and spatial heterogeneity generated during tumor expansion and relapse, which is likely shaped by the complex but ordered processes of multiple clonal selection and evolutionary events.

Oncogenic signaling is dominant to cell of origin and dictates astrocytic or oligodendroglial tumor development from oligodendrocyte precursor cells

Stem cells, believed to be the cellular origin of glioma, are able to generate gliomas, according to experimental studies. Here we investigated the potential and circumstances of more differentiated cells to generate glioma development. We and others have shown that oligodendrocyte precursor cells (OPCs) can also be the cell of origin for experimental oligodendroglial tumors. However, the question of whether OPCs have the capacity to initiate astrocytic gliomas remains unanswered. Astrocytic and oligodendroglial tumors represent the two most common groups of glioma and have been considered as distinct disease groups with putatively different origins. Here we show that mouse OPCs can give rise to both types of glioma given the right circumstances. We analyzed tumors induced by K-RAS and AKT and compared them to oligodendroglial platelet-derived growth factor B-induced tumors in Ctv-a mice with targeted deletions of Cdkn2a (p16(Ink4a-/-), p19(Arf-/-), Cdkn2a(-/-)). Our results showed that glioma can originate from OPCs through overexpression of K-RAS and AKT when combined with p19(Arf) loss, and these tumors displayed an astrocytic histology and high expression of astrocytic markers. We argue that OPCs have the potential to develop both astrocytic and oligodendroglial tumors given loss of p19(Arf), and that oncogenic signaling is dominant to cell of origin in determining glioma phenotype. Our mouse data are supported by the fact that human astrocytoma and oligodendroglioma display a high degree of overlap in global gene expression with no clear distinctions between the two diagnoses.

Surgical strategies for nonenhancing slow-growing gliomas with special reference to functional reorganization: review with own experience

Nonenhancing intrinsic brain tumors have been empirically treated with a strategy that has been adopted for World Health Organization (WHO) grade II gliomas (low-grade gliomas: LGGs), even though small parts of the tumors might have been diagnosed as WHO grade III gliomas after surgery. However, the best surgical strategy for nonenhancing gliomas, including LGGs, is still debatable. LGGs have the following features: slow growth, high possibility of histologically malignant transformation, and no clear border between the tumor and adjacent normal brain. We retrospectively examined 26 consecutive patients with nonenhancing gliomas who were surgically treated at Kanazawa University Hospital between January 2006 and May 2012, with special reference to functional reorganization, extent of resection (EOR), and functional mapping during awake surgery. These categories are closely related with the features of LGG, i.e. functional reorganization due to slow-growing nature, EOR with related malignant transformation, and functional mapping for delineating the unclear tumor border. Finally, we discuss surgical strategies for slow-growing gliomas that are represented by LGGs and nonenhancing gliomas. In conclusion, slow-growing gliomas tend to undergo functional reorganization, and the functional reorganization affects the presurgical evaluation for resectability based on tumor location related to eloquence. In the clinical setting, to definitely identify the reorganized functional regions, awake surgery is recommended. Therefore, awake surgery could increase the extent of the resection of the tumor without deficits, resulting in the delay of malignant transformation and increase in overall survival.

Extent of resection and survival in supratentorial infiltrative low-grade gliomas: analysis of and adjustment for treatment bias

BACKGROUND

Any correlation between the extent of resection and the prognosis of patients with supratentorial infiltrative low-grade gliomas may well be related to biased treatment allocation. Patients with an intrinsically better prognosis may undergo more aggressive resections, and better survival may then be falsely attributed to the surgery rather than the biology of the disease. The present study investigates the potential impact of this type of treatment bias on survival in a series of patients with low-grade gliomas treated at the authors' institution.

METHODS

We conducted a retrospective study of 148 patients with low-grade gliomas undergoing primary treatment at our institution from 1996-2011. Potential prognostic factors were studied in order to identify treatment bias and to adjust survival analyses accordingly.

RESULTS

Eloquence of tumor location proved the most powerful predictor of the extent of resection, i.e., the principal source of treatment bias. Univariate as well as multivariate Cox regression analyses identified the extent of resection and the presence of a preoperative neurodeficit as the most important predictors of overall survival, tumor recurrence and malignant progression. After stratification for eloquence of tumor location in order to correct for treatment bias, Kaplan-Meier estimates showed a consistent association between the degree of resection and improved survival.

CONCLUSION

Treatment bias was not responsible for the correlation between extent of resection and survival observed in the present series. Our data seem to provide further support for a strategy of maximum safe resections for low-grade gliomas.

Epileptic seizures in diffuse low-grade gliomas in adults

Diffuse low-grade gliomas are highly epileptogenic brain tumours. We aimed to explore the natural course of epileptic seizures, their predictors and the prognostic significance of their occurrence in adult patients harbouring a diffuse low-grade glioma. An observational retrospective multicentre study examined 1509 patients with diffuse low-grade gliomas to identify mutual interactions between tumour characteristics, tumour course and epileptic seizures. At diagnosis, 89.9% of patients had epileptic seizures. Male gender (P = 0.003) and tumour location within functional areas (P = 0.001) were independent predictors of a history of epileptic seizures at diagnosis. Tumour volume, growth velocity, cortical location, histopathological subtype or molecular markers did not significantly affect epileptic seizure occurrence probability. Prolonged history of epileptic seizures (P < 0.001), insular location (P = 0.003) and tumour location close to functional areas (P = 0.038) were independent predictors of uncontrolled epileptic seizures at diagnosis. Occurrence of epileptic seizures (P < 0.001), parietal (P = 0.029) and insular (P = 0.002) locations were independent predictors of uncontrolled epileptic seizures after oncological treatment. Patient age (P < 0.001), subtotal (P = 0.007) and total (P < 0.001) resections were independent predictors of total epileptic seizure control after oncological treatment. History of epileptic seizures at diagnosis and total surgical resection were independently associated with increased malignant progression-free (P < 0.001 and P < 0.001) and overall (P < 0.001 and P = 0.016) survivals. Epileptic seizures are independently associated with diffuse low-grade glioma prognosis. Patients diagnosed with epileptic seizures and those with complete and early surgical resections have better oncological outcomes. Early and maximal surgical resection is thus required for diffuse low-grade gliomas, both for oncological and epileptological purposes.

Radiotherapy in low-grade glioma adult patients: a retrospective survival and neurocognitive toxicity analysis

PURPOSE

The treatment of low-grade glioma is still debated. Surgery is the first-line approach, and the correct timing of radiation therapy has not yet been defined since "early" radiation therapy improves relapse-free survival but not overall survival. Since a longer progression-free survival is desirable, the main issue related to radiotherapy is the incidence of late neurocognitive toxicity.

MATERIALS AND METHODS

Ninety-five patients with low-grade glioma were consecutively treated with early (within 3 months) or late (at disease progression) post-surgical radiation therapy. Clinical and therapeutic factors were entered into the analysis overall (OS) and progression-free (PFS) survival, and the distribution in two accrual periods identified based on the evolution of imaging procedures and radiotherapy techniques were compared. For 6/18 long survivors (LS) without evidence of disease, neurocognitive evaluation was obtained and the dose to the hippocampus region was retrospectively calculated.

RESULTS

Univariate analysis of OS showed a statistically significant advantage for grade 1 and oligodendroglioma histology, better performance status [Karnofsky index (KI)], age <40 years, radical surgery, no steroid treatment; PFS was significantly related with younger age, better KI and "early" radiotherapy. Multivariate analysis of OS confirmed the significance of all variables except surgery; for PFS, only "early" radiotherapy and better KI retained significance. Memory impairment was evident in 4/6 of the LS tested; quality of life was good and executive functions were normal.

CONCLUSION

Radiotherapy remains an essential component in the treatment of low-grade glioma. Prospective studies are needed to evaluate the relative contributions of the disease itself and of surgery, radiation and chemotherapy to long-term neurocognitive damage.

A population-based study of low-grade gliomas and mutated isocitrate dehydrogenase 1 (IDH1)

Low-grade gliomas (LGG) have a slow growth rate, but transformations into malignant gliomas with a rapid deterioration occur in many patients. The aim of this study was to evaluate clinical prognostic factors in a population-based cohort of patients with LGG. In addition we investigated the expression and prognostic value of the isocitrate dehydrogenase 1 (IDH1) R132H mutation. Seventy-four patients diagnosed between 2005 and 2009 in the Region of Southern Denmark were identified using the Danish Cancer Register and The Danish Pathology Databank. Survival analysis using Cox regression was performed in 52 patients with tumor samples useable for immunohistochemical evaluation of IDH1 status. Patients with a contrast enhancing tumor, neurological deficits, headache, an astrocytic tumor and PS 2-4 had an increased risk of recurrence. In univariate analysis age > 50 years (HR 2.14, 95 % CI 1.08-4.24), having neurological deficit (HR 2.28, 95 % CI 1.15-4.52), receiving post-surgical treatment (HR 2.52, 95 % CI 1.19-5.32), being in performance status 2-4 (HR 1.44, 95 % CI 1.15-1.81), and having an astrocytic tumor (HR 3.79, 95 % CI 1.64-8.73) were associated with poor survival. Mutated IDH1 (mIDH1) was identified in 46 % of the patients and was significantly correlated to a good survival in both univariate (HR 0.24, 95 % CI 0.11-0.53) and in multivariate analysis (HR 0.40, 95 % CI 0.17-0.91). The other clinical variables were not significant when adjusted for the effect of mIDH1 status. We find that young age, the absence of neurologic deficit, PS 0-1 and oligodendroglial histology were associated with better survival. IDH1 status showed independent prognostic information when adjusting for classical prognostic factors, and should be validated in a larger patient population.

Long-Term Results of stereotactic Brachytherapy (Temporary 125Iodine Seeds) for the Treatment of Low-Grade Astrocytoma (Grade II)

Background

Treatment of low-grade astrocytoma (WHO grade II) (LGA II) remains a challenge. There is limited information regarding the long-term effects of stereotactic brachytherapy (SBT) (temporary ¹²⁵Iodine seeds) on patients with LGA II.

Objectives

The purpose of this study was to evaluate disease control and survival after stereotactic brachytherapy in patients with circumscribed and relatively small size tumors.

Materials and Methods

A retrospective review of 29 patients, treated between 1991 and 2011, was conducted to evaluate survival, complications, and local disease control after stereotactic brachytherapy. They belonged to a larger group of 48 cases with low-grade gliomas, treated with stereotactic brachytherapy. The demographic and clinical characteristics in patients including age, sex, and survival time were extracted from records.

Results

Thirteen patients were male and 16 were female, with the median age of 29 years (range, 2.5 – 64 years). The median follow-up was 95 (range, 6 – 240) months. Based on Pignatti classification, 10 patients were at low- and 19 patients at high-risk. The median overall as well as progression-free survivals for patients were 135 months (95% confidence interval: 76 – 194) and 96 months (95% confidence interval: 1 – 199), respectively. Five- and 10-year progression-free survivals were 41.4 % and 34.5 %, respectively, and the 5- and 10-year overall survivals were 65.5 % and 44.8%, respectively. Progression-free survival was not significantly higher in smaller size tumors (P = 0.224), nor for spherical versus non-spherical tumors (P = 0.307). There was no treatment-related morbidity after stereotactic brachytherapy, and no radiogenic complications occurred during the follow-up period. Mortality due to tumor progression occurred in 4 patients (14%), and 11 patients were alive at the last follow-up.

Conclusions

The stereotactic brachytherapy for patients with circumscribed and relatively small size tumors appears to be a safe, feasible, and minimally-invasive treatment.

Response to postoperative radiotherapy as a prognostic factor for patients with low-grade gliomas

Due to the favorable natural history in patients with low-grade gliomas (LGGs), there is no consensus on the treatment strategy following maximal safe surgical resection. A number of studies have been conducted to identify prognostic factors in patients treated for LGG. The present study evaluated the treatment outcomes as well as prognostic factors and their impact on overall survival (OS) and disease-free survival (DFS). We retrospectively reviewed 30 consecutive patients treated for LGG at the Department of Radiotherapy from February 2008 to July 2011. The patients underwent surgical intervention and postoperative radiotherapy. The response to radiotherapy was evaluated from six to eight weeks after the end of treatment using MRI analysis. Kaplan-Maier analysis was used for OS and DFS estimation. The endpoint was mortality as a result of any cause. Within a median follow-up of 21.8 months, 9 patients (30%) with disease progression were reported. The two- and five-year DFS and OS was 85.2 and 68.3% for DFS, and 84.3 and 63.4% for OS, respectively. The response to radiotherapy, evaluated in an MRI study, was found to be highly correlated with OS (p<0.0001). We also observed a significantly higher OS in patients with disease progression treated with salvage chemotherapy after the end of radiotherapy (p=0.08). Improved outcome among patients with LGG may be predicted by response to radiotherapy evaluated by MRI following termination of treatment.

Molecular genetics of adult grade II gliomas: towards a comprehensive tumor classification system

Adult grade II low-grade gliomas (LGG) are classified according to the WHO as astrocytomas, oligodendrogliomas or mixed gliomas. TP53 mutations and 1p19q codeletion are the main molecular abnormalities recorded, respectively, in astrocytomas and oligodendrogliomas and in mixed gliomas. Although IDH mutations (IDH1 or IDH2) are recorded in up to 85 % of low-grade gliomas, IDH negative gliomas do occur. We have searched for p53 expression, 1p19q codeletion and IDH status (immunohistochemical detection of the common R132H IDH1 mutation and IDH direct sequencing). Internexin alpha (INA) expression previously recorded to be associated with 1p19q codeletion (1p19q+) gliomas was also analysed. Low-grade gliomas were accurately classified into four groups: group 1, IDH+/p53-/1p19q-; group 2, IDH+/p53-/1p19q+; group 3, IDH+/p53+/1p19q-; and group 4, triple negative gliomas. In contrast to the WHO classification, this molecular classification predicts overall survival on uni- and multivariate analysis (P = 0.001 and P = 0.007, respectively). Group 4 carries the worst prognosis and group 2 the best. Interestingly, p53 +/INA- expression predicts lack of 1p19q codeletion (specificity 100 %, VPP 100 %). The combined use of these three molecular markers allow for an accurate prediction of survival in LGG. These findings could significantly modify LGG classification and may represent a new tool to guide patient-tailored therapy. Moreover, immunohistochemical detection of p53, INA and mR132H IDH1 expression could represent an interesting prescreening test to be performed before 1p19q codeletion, IDH1 minor mutation and IDH2 mutation detection.

Long-term epilepsy-associated tumors

The term long-term epilepsy associated tumor (LEAT) encompasses lesions identified in patients investigated for long histories (often 2 years or more) of drug-resistant epilepsy. They are generally slowly growing, low grade, cortically based tumors, more often arising in younger age groups and in many cases exhibit neuronal in addition to glial differentiation. Gangliogliomas and dysembryoplastic neuroepithelial tumors predominate in this group. LEATs are further united by cyto-architectural changes that may be present in the adjacent cortex which have some similarities to developmental focal cortical dysplasias (FCD); these are now grouped as FCD type IIIb in the updated International League Against Epilepsy (ILAE) classification. In the majority of cases, surgical treatments are beneficial from both perspectives of managing the seizures and the tumor. However, in a minority, seizures may recur, tumors may show regrowth or recurrence, and rarely undergo anaplastic progression. Predicting and identifying tumors likely to behave less favorably are key objectives of the neuropathologist. With immunohistochemistry and modern molecular pathology, it is becoming increasingly possible to refine diagnostic groups. Despite this, some LEATs remain difficult to classify, particularly tumors with "non-specific" or diffuse growth patterns. Modification of LEAT classification is inevitable with the goal of unifying terminological criteria applied between centers for accurate clinico-pathological-molecular correlative data to emerge. Finally, establishing the epileptogenic components of LEAT, either within the lesion or perilesional cortex, will elucidate the cellular mechanisms of epileptogenesis, which in turn will guide optimal surgical management of these lesions.

Current treatment of low grade astrocytoma: a review

Through a comprehensive review of the current literature, the present article investigates several aspects of low grade astrocytomas (LGA), including prognostic factors, treatment strategies and follow-up regimes. LGA are in general relatively slow-growing primary brain tumours, but they have a very heterogeneous clinical behaviour. Several factors affect prognosis, and these include age, histological subtype, and Karnofsky Performance Score (KPS) prior to surgery. Furthermore, a number of different molecular genetic alterations have been shown to affect both the prognosis as well as the course of disease. The current literature seems to support the idea that treatment with radical tumour resection, where possible, yields better long term outcome for patients with LGA. However, adjuvant therapy is often necessary. Administering early postoperative radiotherapy to patients with partially resected LGA yields a longer period of progression-free survival, whereas patients with radically resected tumours should receive radiotherapy at the time of progression. Regarding chemotherapy, we found evidence to suggest that patients respond to both temozolomide (TMZ) and the combination of procarbazine, lomustine and vincristine (PCV). However, the response rates in patients receiving PCV seem superior to those of patients receiving TMZ. In follow-up PET scans, the tracers (18)F-FDG and MET provide high sensitivities for detection of new suspicious lesions and these tracers are furthermore effective in discriminating between tumour progression and radiation necrosis. The research into biomarkers is currently limited with regards to their applications in LGA diagnostics, and therefore further studies including larger patient populations are needed.

IDH1/2 mutation is a prognostic marker for survival and predicts response to chemotherapy for grade II gliomas concomitantly treated with radiation therapy

Reliable prognostic biomarkers of grade II gliomas remain unclear. This study aimed to examine the role of mutations of isocitrate dehydrogenase (IDH1/2), 1p/19q co-deletion, and clinicopathological factors in patients with grade II glioma who were primarily treated with radiotherapy or chemoradiotherapy after surgery. Seventy-two consecutive patients, including 49 cases of diffuse astrocytomas (DA), 4 oligodendrogliomas (OL) and 19 oligoastrocytomas (OA), who underwent treatment from 1991 to 2010 at a single institution were examined. The overall survival (OS) of the DA patients (8.3 years) was significantly shorter than that of the OL and OA patients (11.7 years). IDH1/2 mutations were found in 46.9% of the DA patients and 82.6% of the OL and OA patients. The progression-free survival (PFS) and OS of the patients with IDH1/2 mutations (8.4 and 16.3 years) were significantly longer than those of the patients without IDH1/2 mutations (3.3 and 4.5 years). Among the patients with IDH1/2 mutations, those who were initially treated with chemoradiotherapy including nimustine hydrochloride (ACNU), had significantly longer PFS than those treated with radiotherapy alone, whereas no significant difference in PFS was observed between the chemoradiotherapy and radiotherapy groups in the patients without IDH1/2 mutations. Oligodendroglial tumors, age <40 years, initial Karnofsky performance status (KPS) ≥80, and IDH1/2 mutations were favorable prognostic factors regarding PFS and OS. IDH1/2 mutation was a predictive factor of response to chemoradiotherapy in grade II gliomas. Patients with IDH1/2 mutations may benefit more from chemoraiotherapy than those without IDH1/2 mutations.

Seizures and the natural history of World Health Organization Grade II gliomas: a review

OBJECTIVE

The majority of adults with low-grade gliomas have seizures. Despite the frequency of seizures as initial symptoms and symptoms of later disease, seizures in relation to the natural course of low-grade gliomas have received little attention.

METHODS

In this review, we provide an update of the literature on the prognostic impact of preoperative seizures and discuss the tumor- and treatment-related factors affecting seizure control at later stages of the disease.

RESULTS

Seizures occur most frequently at disease presentation and predict a more favorable outcome. Initial seizures are correlated with tumor location and possibly indirectly to the molecular profile of the tumor. About 50% of all patients with seizures at presentation continue to have seizures before surgery. Maximal tumor resection, including resection of epileptic foci, is a valuable strategy for improving seizure control. In addition, radiotherapy and chemotherapy, as single therapies or in combination with surgery, have shown beneficial effects in terms of seizure reduction. Recurrent seizures after macroscopically complete tumor resection may be a marker for accelerated tumor growth. Recurrent seizures after an initial transient stabilization after radiotherapy and/or chemotherapy may be a marker for anaplastic tumor transformation.

CONCLUSION

Preoperative seizures likely reflect, apart from tumor location, intrinsic tumor properties as well. Change in seizure control in individual patients is frequently associated with altered tumor behavior. Including seizures and seizure control as clinical parameters is recommended in future trials of low-grade gliomas to further establish the prognostic value of these symptoms and to identify the factors affecting seizure control.

The impact of extent of resection and histological subtype on the outcome of adult patients with high-grade gliomas

OBJECTIVE

We reviewed the relationship between extent of resection and survival of patients with high-grade gliomas with special consideration of an oligodendroglial component.

METHODS

A retrospective review was performed on 160 adult patients with histological diagnosis of high-grade gliomas since 2000. All histological slides were categorized as high-grade astrocytomas or oligodendroglial tumors. Extent of resection was assessed by early post-operative magnetic resonance imaging and classified as complete resection, incomplete resection and biopsy. Measured outcomes were overall survival and progression-free survival. The independent association of extent of resection and survival was analyzed by the multivariate proportional hazard model adjusting for prognostic factors.

RESULTS

The lesions were classified as high-grade astrocytomas in 93 patients and high-grade oligodendroglial tumors in 67 patients. In high-grade astrocytomas, the median survival after complete resection (n = 36), incomplete resection (n = 36) and biopsy (n = 21) was 23.4, 15.3 and 12.6 months, respectively. Complete resection was independently associated with increased overall survival (P < 0.001) and progression-free survival (P = 0.002) compared with incomplete resection, while incomplete resection was not associated with survival benefit compared with biopsy by multivariate analysis. On the other hand, in high-grade oligodendroglial tumors, the majority of patients were still alive and there is no significant difference in the survival between complete resection (n = 24) and incomplete resection (n = 33), while even incomplete resection had a significantly longer overall survival (P < 0.001) and progression-free survival (P = 0.006) compared with biopsy (n = 10).

CONCLUSIONS

Maximal cytoreduction improves the survival of high-grade gliomas, although our data indicated that the impact of extent of resection in high-grade astrocytomas is different from that in high-grade oligodendroglial tumors.

Long-term follow-up in adult patients with low-grade glioma (WHO II) postoperatively irradiated. Analysis of prognostic factors

AIM

To report the long-term follow-up of a cohort of adult patients with LGG post-operatively irradiated in one institution, and to identify prognostic factors for progression free survival.

BACKGROUND

There is little consensus about the optimal treatment for low-grade glioma (LGG), and the clinical management of LGG is one of the most controversial areas in neurooncology. Radiation therapy is one option for treatment of patients with LGG, whereas other options include postoperative observation.

MATERIALS AND METHODS

Between 1975 and 2005, 180 patients with LGG (WHO II) received postoperative irradiation after non radical (subtotal or partial) excision. Patients had to be 18 years of age or older, and have histologic proof of supratentorial fibrillary (FA), protoplasmic (PA) or gemistocytic astrocytoma (GA). Radiotherapy was given within 3-10 weeks after surgery. Treatment fields were localized and included the preoperative tumor volume, with a 1-2 cm margin, treated to a total dose of 50-60 Gy in 25-30 fractions over 5-6 weeks.

RESULTS

Actuarial ten-year progression free survival (APFS) in the whole group was 19%. The worse prognosis was observed in patients with GA. Ten-year APFS rates for GA, PA and FA were 10%, 18% and 22%, respectively.

CONCLUSION

The findings from our long-term cohort of 180 patients with LGG confirmed by uni- and multivariate analysis demonstrated that only astrocytoma histology significantly determined the prognosis. The best survival was observed in patients with the fibrillary variant, and the worst for the gemistocytic one.

Low-grade gliomas in adults

In recent years, advances in the understanding of low-grade glioma (LGG) biology have driven new paradigms in molecular markers, diagnostic imaging, operative techniques and technologies, and adjuvant therapies. Taken together, these developments are collectively pushing the envelope toward improved quality of life and survival. In this article, the authors evaluate the recent literature to synthesize a comprehensive review of LGGs in the modern neurosurgical era.

Extent of resection influences outcomes for patients with gliomas

In recent years, advances in our understanding of the biology of low-grade gliomas (LGG) and high-grade gliomas (HGG) have driven new paradigms in molecular markers, diagnostic imaging, operative techniques and technologies, and adjuvant therapies. Taken together, these developments are collectively pushing the envelope towards improved quality of life and survival. Here, we review the recent literature to synthesize a comprehensive review of the value of extent of resection for LGGs and HGGs in the modern neurosurgical era.

Neurocytomas: long-term experience of a single institution

There is a lack of studies reporting on outcomes of control and treatment toxicities for neurocytomas. A 25-year retrospective review of a tertiary center's experience with neurocytomas was completed to report on these outcomes. All cerebral neurocytoma cases (19 patients; median age, 31 years; range, 18-62 years; 18 intraventricular and 1 extraventricular) treated between 1984 and 2009 were analyzed, including central pathology and radiology reviews. Median follow-up was 104.5 months (range, 0.75-261.7 months). Primary treatment was surgery alone (n = 18 patients), followed by surgery and adjuvant radiotherapy (n = 1). The crude local control rate after surgery was 68% for all cases (cerebral neurocytomas) and 74% for central neurocytomas. Salvage therapies included further surgery (n = 4), radiation (n = 3), and chemotherapy (n = 1). Ten-year Kaplan-Meier overall and relapse-free survival rates were 82% and 62% and 81% and 57%, respectively, for all cases and for central neurocytomas only. The median overall survival and relapse-free survival were 104.5 and 79.3 months, respectively, for all cases and for central neurocytomas. Ten patients had grade 3/4 toxicity, and 1 patient had a grade 5 perioperative hemorrhage that resulted in death 23 days after surgery. Late grade 3/4 toxicities occurred in 9 patients. Three patients had permanent grade 2 motor or cognitive deficits. We provide the first report outlining toxicities and survival outcomes in a series of 19 patients. Our experience suggests that initial surgery provides durable local control rates in two-thirds of patients, with low risk for significant permanent deficits. Salvage therapy with surgery and/or radiation provides durable local control in tumors that recur after surgery.